Fix Gecko code handler: - Store the codes in some imaginary memory past the end of MEM1 to avoid size limits, and patch the codehandler to use this memory. - Don't single step on every frame in order to detect when the codehandler has finished running, which could be slow. Instead, make a HLE function to restore LR/PC/R1 to the pre-codehandler values and have the codehandler return to that.